Revert "Move CI to Git submodule"

This reverts commit 86d0b37713.

.gitmodules

@@ -1,3 +0,0 @@
-[submodule ".woodpecker"]
-	path = .woodpecker
-	url = https://git.k-space.ee/k-space/container-image-pipeline

.woodpecker/build.yaml

@@ -0,0 +1,26 @@
+---
+matrix:
+  ARCH:
+    - amd64
+    - arm64
+
+steps:
+  - name: build
+    image: woodpeckerci/plugin-kaniko
+    backend_options:
+      kubernetes:
+        nodeSelector:
+          kubernetes.io/arch: ${ARCH}
+        tolerations:
+          - key: arch
+            operator: Equal
+            value: ${ARCH}
+            effect: NoSchedule
+    settings:
+      repo: ${CI_REPO}
+      registry: harbor.k-space.ee
+      tags: latest-${ARCH}
+      username:
+        from_secret: docker_username
+      password:
+        from_secret: docker_password

.woodpecker/manifest.yaml

@@ -0,0 +1,31 @@
+---
+skip_clone: true
+
+steps:
+  - name: manifest
+    image: mirror.gcr.io/mplatform/manifest-tool:alpine-v2.1.6
+    secrets:
+      - docker_username
+      - docker_password
+    commands:
+      - set -u
+      - ls -lash
+      - env
+      - |
+        cat << EOF > spec.yaml
+        image: "harbor.k-space.ee/${CI_REPO}:latest"
+        manifests:
+          - image: "harbor.k-space.ee/${CI_REPO}:latest-amd64"
+            platform:
+              architecture: amd64
+              os: linux
+          - image: "harbor.k-space.ee/${CI_REPO}:latest-arm64"
+            platform:
+              architecture: arm64
+              os: linux
+        EOF
+      - /manifest-tool --username $docker_username --password $docker_password push from-spec spec.yaml > stdout
+      - cat stdout
+
+depends_on:
+  - build